Response of pepper plants to different rates of mineral fertilizers after soil biofumigation and solarization

A greenhouse experiment was conducted to examine the effect of using three different rates (zero, low-input, and high-input) of a mineral fertilizer (nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)) on growth and yield of pepper cultivated in a soil after biofumigation (with horse manure at the rate of 4 kg center dot m(-2)) and solarization. Several physiological traits related with pepper plant development (leaf mineral concentration, net photosynthesis rate, transpiration, leaf sugar, and chlorophyll concentration) and fruit yield were determined. In T-1, chlorophyll was significantly lower and sugar concentration was significantly higher than in those where mineral fertilizers had been added (T-2 and T-3). There were no significant differences in photosynthetic rate among treatments. Increasing mineral fertilizer rates increased vegetative growth at the expense of fruit yield. Leaf nutrient concentrations most affected by the treatments were the N-fractions, and changes in the other parameters measured are discussed on the basis of these differences.